Golf balls with cores or intermediate layers prepared from highly-neutralized ethylene copolymers and organic acids

ABSTRACT

Disclosed are golf balls comprising cores or intermediate layers prepared from thermoplastic compositions having coefficients of restitution equal to or greater than 0.83 and PGA compressions greater than 100. Also disclosed is a composition comprising or prepared from (a) at least one aliphatic, mono-functional organic acid having from 16 to 20 carbon atoms, wherein the organic acid is unsaturated and linear; (b) an ethylene acid copolymer consisting essentially of copolymerized comonomers of ethylene and from 18 to 24 weight % of copolymerized comonomers of at least one C 3  to C 8  α,β ethylenically unsaturated carboxylic acid, based on the total weight of the ethylene acid copolymer, having a melt index from about 200 to about 600 g/10 minutes; wherein the combined acid moieties of (a) and (b) are nominally neutralized to a level from about 120% to about 200%; and optionally (c) filler.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority to U.S. Provisional Appln. No.61/001,454, filed on Nov. 1, 2007, which is incorporated herein byreference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to golf balls with cores or intermediate layersprepared from melt-processible thermoplastic compositions comprisingorganic acids or salts of organic acids and neutralized copolymers ofethylene and C₃ to C₈ α,β ethylenically unsaturated carboxylic acids.

2. Description of Related Art

Several patents and publications are cited in this description in orderto more fully describe the state of the art to which this inventionpertains. The entire disclosure of each of these patents andpublications is incorporated by reference herein.

Premium golf balls include wound balls, two-piece balls and multilayeredballs. Wound balls may have a spherical molded center, elastomericthread-like material wound around the center, and either a thermoplasticor thermoset cover. Two-piece balls have a spherical molded core coveredwith a thin layer of thermoplastic or thermoset material. Multilayeredballs have a spherical molded core, a cover, and one or moreintermediate layers between the core and the cover.

Centers for wound balls and cores for two-piece and multi-layer ballshave been made using a thermoset rubber such as polybutadiene rubber.With thermoset rubber, complex multi-step processes are needed to makecores and centers. These processes result in scrap that is difficult torecycle. Attempts to solve these difficulties by substituting athermoplastic for the thermoset rubber have had limited success.

Thermoplastic ionomers of copolymers of alpha olefins, particularlyethylene, and C₃₋₈ α,β ethylenically unsaturated carboxylic acids havefound utility in golf ball components such as covers, and otherapplications. U.S. Pat. No. 3,264,272 teaches methods for making suchionomers. The acid copolymers on which the ionomers are based may beprepared as described in U.S. Pat. No. 4,351,931.

Some ionomer compositions, and golf ball covers comprising thesecompositions, are described in U.S. Pat. Nos. 5,688,869; 6,150,470;6,277,921; 6,433,094; 6,451,923; 6,573,335 and 6,800,695. The ionomercompositions comprise metal cation neutralized high acid ionomer resinscomprising copolymers of greater than 16% by weight of analpha,beta-unsaturated carboxylic acid and the balance an alpha-olefin,of which about 10 to about 90% of the acid groups of the copolymer areneutralized with metal cations.

Ionomers have also been modified with fatty acids. For example, U.S.Pat. No.6,777,472 describes a thermoplastic composition that ismelt-processible consisting essentially of (a) from 20 to 45 weight %aliphatic, mono-functional organic acid(s) having fewer than 36 carbonatoms or salt(s) thereof; and (b) ethylene, C₃ to C₈ alpha,betaethylenically unsaturated carboxylic acid copolymer(s) ormelt-processible ionomer(s) thereof, wherein greater than 90% of all theacid of (a) and (b) is neutralized by concurrently or subsequentlyadding to the melt blend of (a) and (b) an amount of a cation sourcenecessary to obtain greater than 90% neutralization.

Modified ionomers have been used as golf ball components. U.S. Pat. No.6,565,456 describes multilayer golf balls comprising a solid core, asurrounding layer, an intermediate layer and a cover, wherein at leastone of the surrounding layer, the intermediate layer or the cover isformed of a heated mixture comprising (a) an olefin-carboxylicacid-optional carboxylate random copolymer and/or (d) a metalion-neutralized olefin-carboxylic acid-optional carboxylate randomcopolymer; (b) a fatty acid or derivative; and (c) a neutralizing basicinorganic metal compound.

It is desirable to provide a high performance material to be used in thecores, centers or intermediate layers of golf balls.

SUMMARY OF THE INVENTION

Provided herein is a golf ball comprising a core and a cover andoptionally at least one intermediate layer positioned between the coreand the cover, wherein the core or an intermediate layer when presentcomprises or is prepared from a thermoplastic composition, wherein thethermoplastic composition when formed into a sphere of 1.50 to 1.68inches in diameter has a coefficient of restitution (“COR”) equal to orgreater than 0.860 or 0.870, if the thermoplastic composition isunfilled, and greater than 0.830 or 0.845 or 0.850, if the thermoplasticcomposition further comprises a filler. The coefficient of restitutionis measured by firing the sphere at an initial velocity of 125feet/second against a steel plate positioned 3 feet from the point whereinitial velocity is determined and dividing the velocity of rebound fromthe plate by the initial velocity. The thermoplastic composition alsohas a PGA compression greater than 100.

Further provided are golf balls wherein the thermoplastic composition isas described below.

In addition, the thermoplastic composition may comprise or preparedfrom:

(a) at least one aliphatic, monofunctional organic acid having 4 to 36carbon atoms, wherein the longest carbon chain of the acid is optionallysubstituted with from one to three substituents independently selectedfrom C₁ to C₈ alkyl groups; and

(b) an ethylene acid copolymer consisting essentially of copolymerizedcomonomers of ethylene and from 18 to 24 weight % of copolymerizedcomonomers of at least one C₃ to C₈ α,β ethylenically unsaturatedcarboxylic acid, based on the total weight of the ethylene acidcopolymer, having a melt index from about 200 to about 600 g/10 minutesmeasured according to ASTM D1238 at 190° C. using a 2160 g weight;

wherein the combined acid moieties of (a) and (b) are nominallyneutralized to a level from about 120% to about 200%; and optionally

(c) filler.

DETAILED DESCRIPTION OF THE INVENTION

The following definitions apply to the terms as used throughout thisspecification, unless otherwise limited in specific instances.

The technical and scientific terms used herein have the meanings thatare commonly understood by one of ordinary skill in the art to whichthis invention belongs. In case of conflict, the present specification,including the definitions herein, will control.

As used herein, the terms “comprises,” “comprising,” “includes,”“including,” “containing,” “characterized by,” “has,” “having” or anyother variation thereof, are intended to cover a non-exclusiveinclusion. For example, a process, method, article, or apparatus thatcomprises a list of elements is not necessarily limited to only thoseelements but may include other elements not expressly listed or inherentto such process, method, article, or apparatus.

The transitional phrase “consisting of” excludes any element, step, oringredient not specified in the claim, closing the claim to theinclusion of materials other than those recited except for impuritiesordinarily associated therewith. When the phrase “consists of” appearsin a clause of the body of a claim, rather than immediately followingthe preamble, it limits only the element set forth in that clause; otherelements are not excluded from the claim as a whole.

The transitional phrase “consisting essentially of” limits the scope ofa claim to the specified materials or steps and those that do notmaterially affect the basic and novel characteristic(s) of the claimedinvention. A ‘consisting essentially of’ claim occupies a middle groundbetween closed claims that are written in a ‘consisting of’ format andfully open claims that are drafted in a ‘comprising’ format. Optionaladditives as defined herein, at levels that are appropriate for suchadditives, and minor impurities are not excluded from a composition bythe term “consisting essentially of”.

When a composition, a process, a structure, or a portion of acomposition, a process, or a structure, is described herein using anopen-ended term such as “comprising,” unless otherwise stated thedescription also includes an embodiment that “consists essentially of”or “consists of” the elements of the composition, the process, thestructure, or the portion of the composition, the process, or thestructure.

The articles “a” and “an” may be employed in connection with variouselements and components of compositions, processes or structuresdescribed herein. This is merely for convenience and to give a generalsense of the compositions, processes or structures. Such a descriptionincludes “one or at least one” of the elements or components. Moreover,as used herein, the singular articles also include a description of aplurality of elements or components, unless it is apparent from aspecific context that the plural is excluded.

The term “or”, as used herein, is inclusive; that is, the phrase “A orB” means “A, B, or both A and B”. More specifically, a condition “A orB” is satisfied by any one of the following: A is true (or present) andB is false (or not present); A is false (or not present) and B is true(or present); or both A and B are true (or present). Exclusive “or” isdesignated herein by terms such as “either A or B” and “one of A or B”,for example.

The term “about” means that amounts, sizes, formulations, parameters,and other quantities and characteristics are not and need not be exact,but may be approximate and/or larger or smaller, as desired, reflectingtolerances, conversion factors, rounding off, measurement error and thelike, and other factors known to those of skill in the art. In general,an amount, size, formulation, parameter or other quantity orcharacteristic is “about” or “approximate” whether or not expresslystated to be such.

Unless stated otherwise, all percentages, parts, ratios, and likeamounts, are defined by weight. In addition, the ranges set forth hereininclude their endpoints unless expressly stated otherwise. Further, whenan amount, concentration, or other value or parameter is given as arange, one or more preferred ranges or a list of upper preferable valuesand lower preferable values, this is to be understood as specificallydisclosing all ranges formed from any pair of any upper range limit orpreferred value and any lower range limit or preferred value, regardlessof whether such pairs are separately disclosed. The scope of theinvention is not limited to the specific values recited when defining arange.

When materials, methods, or machinery are described herein with the term“known to those of skill in the art”, “conventional” or a synonymousword or phrase, the term signifies that materials, methods, andmachinery that are conventional at the time of filing the presentapplication are encompassed by this description. Also encompassed arematerials, methods, and machinery that are not presently conventional,but that will have become recognized in the art as suitable for asimilar purpose.

As used herein, the term “copolymer” refers to polymers comprisingcopolymerized units resulting from copolymerization of two or morecomonomers. In this connection, a copolymer may be described herein withreference to its constituent comonomers or to the amounts of itsconstituent comonomers, for example “a copolymer comprising ethylene and18 weight % of acrylic acid”, or a similar description. Such adescription may be considered informal in that it does not refer to thecomonomers as copolymerized units; in that it does not include aconventional nomenclature for the copolymer, for example InternationalUnion of Pure and Applied Chemistry (IUPAC) nomenclature; in that itdoes not use product-by-process terminology; or for another reason. Asused herein, however, a description of a copolymer with reference to itsconstituent comonomers or to the amounts of its constituent comonomersmeans that the copolymer contains copolymerized units (in the specifiedamounts when specified) of the specified comonomers. It follows as acorollary that a copolymer is not the product of a reaction mixturecontaining given comonomers in given amounts, unless expressly stated inlimited circumstances to be such. The term “dipolymer” refers topolymers consisting essentially of two monomers.

Provided herein are thermoplastic compositions having a coefficient ofrestitution (COR) greater than 0.870. Preferred thermoplasticcompositions include an organic acid or a salt of an organic acid, anionomer of an acid copolymer, and, optionally, a filler. When thethermoplastic composition comprises a filler, however, its COR isgreater than 0.830, greater than 0.845, or greater than 0.850, forreasons discussed at length below.

Acid Copolymers

The acid copolymers used to make the thermoplastic compositionsdescribed herein are preferably “direct” acid copolymers. In “direct”copolymers, the copolymerized monomers are part of the polymer backboneor chain. In contrast, in graft copolymers, another comonomer isattached to non-terminal repeat units in an existing polymer chain,often by a subsequent free radical reaction.

When combined with other components as described herein, an ethylenedipolymer consisting essentially of copolymerized comonomers of ethyleneand from about 18 to about 24 weight % of copolymerized comonomers of C₃to C₈ α,β ethylenically unsaturated carboxylic acid is particularlyuseful for preparing thermoplastic compositions having coefficients ofrestitution greater than 0.830 or 0.845 or 0.850, if the thermoplasticcomposition further comprises a filler, or greater than 0.860 or 0.870,if the thermoplastic composition is unfilled. Preferably, the dipolymermay include about 19 to about 21 weight % of the copolymerizedcarboxylic acid.

Preferred are dipolymers and compositions comprising the dipolymerswherein the copolymerized comonomers of C₃ to C₈ α,β ethylenicallyunsaturated carboxylic acid are acrylic acid or methacrylic acid.Specific acid copolymers include ethylene/acrylic acid dipolymers andethylene/methacrylic acid dipolymers. More preferably, the dipolymer mayinclude 19 to 20 weight % of copolymerized methacrylic acid, or about 21weight % of copolymerized acrylic acid.

Ethylene/acrylic acid dipolymers are of note because acrylic acid willprovide more acid moieties than an equal weight of methacrylic acid.

Ethylene acid dipolymers with high levels of acid may be preparedthrough the use of “co-solvent technology” as described in U.S. Pat. No.5,028,674 or by employing somewhat higher pressures than those at whichcopolymers with lower acid levels may be prepared.

The dipolymer resins have melt index flow rates in the range of about200 g/10 min to about 600 g/10 min, or greater, at 190° C. using a 2160g weight, such as dipolymer resins having melt index flow rates fromabout 300 g/10 min to about 550 g/10 min at 190° C. using a 2160 gweight.

Ionomers

Unmodified, melt processible ionomers may be prepared from acidcopolymers described above by methods known in the art. By “unmodified”,it is meant that the ionomers are not blended with any material that hasbeen added for the purpose of modifying the properties of the unblendedionomer. Ionomers include partially neutralized acid copolymers,particularly copolymers prepared from copolymerization of ethylene andacrylic acid or methacrylic acid. The unmodified ionomers may beneutralized to any level that does not result in an intractable (notmelt processible) polymer that does not have useful physical properties.Preferably, about 15 to about 90%, more preferably about 50 to about 75%of the acid moieties of the acid copolymer are neutralized to formcarboxylate groups. Preferred counterions for the carboxylate groupsinclude alkali metal cations, alkaline earth metal cations, transitionmetal cations, and combinations of two or more of these metal cations.

More specifically, cations useful in the unmodified ionomers includelithium, sodium, potassium, magnesium, calcium, barium, or zinc, orcombinations of two or more of these cations. Magnesium cations orcalcium cations are preferred.

Organic Acids and Salts

Suitable organic acids include, without limitation, aliphatic,monofunctional organic acids having 4 to 36 carbon atoms, wherein thelongest carbon chain may optionally be substituted with from one tothree substituents independently selected from C₁ to C₈ alkyl groups.The organic acids may be saturated or unsaturated, and, if unsaturated,may include more than one carbon-carbon double bond. The term“mono-functional” refers to acids with one carboxylic acid moiety.Suitable organic acids include C₄ to C₃₆ (for example C₁₈), moreparticularly C₆ to C₂₆, and even more particularly C₆ or C₁₂ or C₁₆ toC₂₄ acids.

Specific examples of suitable organic acids include, but are not limitedto, caproic acid, caprylic acid, capric acid, lauric acid, stearic acid,isostearic acid, behenic acid, erucic acid, oleic acid, iso-oleic acid,and linoleic acid. Naturally derived organic fatty acids such aspalmitic, stearic, oleic, erucic, behenic acids, and mixtures thereofmay also be employed.

As is well known in the art, commercial grades of organic acids mayinclude a number of structurally different organic acids of varyinglesser amounts. As used herein, unless otherwise specified in limitedcircumstances, a composition that comprises a named acid may alsoinclude other acids that are present in commercial grades of the namedacid, at levels that are proportional to their levels in the commercialgrade. Furthermore, when the transitional term “consisting essentiallyof” is applied to compositions that comprise a named acid, other acidsthat are present in commercial grades of the named acid, at levels thatare proportional to their levels in the commercial grade, are notexcluded from the composition.

Saturated acids of note include stearic acid and behenic acid. Saturatedlinear organic acids (such as stearic acid and behenic acid) are acidscomprising only one CH₃ (methyl) and no CH (methenyl) moieties.

Unsaturated linear organic acids (for example oleic acid and erucicacid) are acids that have only one CH₃ moiety and at least onecarbon-carbon double bond. They include any number of CH₂ (methylene)groups, within the carbon count limits set forth above. Monounsaturatedacids contain one carbon-carbon double bond. Of note are linear,unsaturated (including multi-unsaturated) organic acids having from 16to 24 carbon atoms, including but not limited to oleic acid, erucic acidand linoleic acid. Naturally derived organic fatty acids such as(notably) oleic acid, and mixtures thereof, may be used. Oleic acid iscommercially available under the tradenames INDUSTRENE 106 or INDUSTRENE206 (PMC Biogenix of Middlebury, Conn.) or PRIOLENE 6900 or PRIOLENE6910 (Croda Uniqema of New Castle, Del.).

Acids wherein the longest carbon chain of the acid is substituted withfrom one to three C₁ to C₈ alkyl substituents, preferably methyl groups,are referred to herein as branched acids. Saturated, branched organicacids are acids comprising at least one CH (methenyl) moiety and atleast two CH₃ (methyl) moieties. Of note are saturated, branched organicacids wherein the longest carbon chain of the acid is substituted withone C₁ to C₈ alkyl group. Also of note is a saturated, branched organicacid, preferably having from 6 to 24 carbon atoms, such as the C₁₈saturated branched organic acid iso-stearic acid, also known asisooctadecanoic acid or 16-methyl-heptadecanoic acid.

Unsaturated branched acids are acids comprising at least onecarbon-carbon double bond, at least two CH₃ (methyl) moieties and atleast one CH (methenyl) moiety. They may include any number of CH₂(methylene) groups, within the molecular weight limits set forth above.Of note are unsaturated, branched organic acids wherein the longestcarbon chain of the acid is substituted with one C₁ to C₈ alkyl group.Also of note is an unsaturated, branched organic acid, preferably havingfrom 6 to 24 carbon atoms, such as the C₁₈ monounsaturatedmethyl-branched organic acid known as iso-oleic acid.

While it may be useful for the organic acids (and salts) to have a lowvolatility when being melt-blended with the acid copolymer or ionomer,volatility has been found to not be limiting when preparing blends withhigh nominal neutralization levels, particularly above 100%. At 100%nominal neutralization (i.e., sufficient basic compound is added suchthat all acid moieties in the copolymer and organic acid are nominallyneutralized), or when the use of an excess of neutralizing agent resultsin a nominal neutralization level that is even greater than 100%, thevolatility of these components is not significant. Accordingly, organicacids with lower molecular weights, such as C₄ and C₆ acids, may beused. It is preferred, however, that the organic acid (or salt) benon-volatile and non-migratory. By non-volatile, it is meant that theydo not evaporate or sublimate significantly at temperatures of meltblending of the organic acid with the acid copolymer or ionomer. Bynon-migratory, it is meant that the acid does not bloom to the surfaceof the polymeric article under normal storage conditions at ambienttemperatures.

Preferably the organic acids are present in about 5 weight % to about 60weight %, and more preferably, from about 30 to about 50 weight % orfrom about 35 to about 46 weight % of the total weight of ionomer andorganic acid salt, based on the amount of organic acid added to thecomposition in its non-neutralized or free-acid form. It is understoodthat the upper limits of these weight percentages may be exceeded, ifsubstantially all of the organic acids are neutralized to form salts.

Suitable and preferred cations for the organic acid salts are as setforth above with respect to ionomers. Again, magnesium salts or calciumsalts are preferred.

Process for Making the Ionomer Composition

The melt-processible, modified ionomer blends may be produced by heatinga mixture of the carboxylic acid copolymer(s) or ionomer(s), the organicacid(s) or salt(s) thereof, and at least one basic compound capable ofneutralizing the combined acid moieties of the acid copolymer and theorganic acid. For example, the components of the composition may bemixed by

-   -   (a) Melt-blending ethylene α,β-ethylenically unsaturated C₃₋₈        carboxylic acid copolymer(s) or ionomer(s) thereof as described        above that are not neutralized to a level that renders them        intractable (not melt-processible) with one or more organic        acids as described above or salts thereof, and concurrently or        subsequently    -   (b) Adding an amount of a basic compound capable of        neutralization of the acid moieties in the acid copolymer and in        the organic acid that is sufficient to achieve nominal        neutralization levels of about 120% to about 200% or above.

This procedure need not employ an inert diluent such as a solvent.Treatment of acid copolymers and organic acids with basic compounds inthis way enables the compositions described herein to be neutralized toa level higher than that which would result in loss of meltprocessibility and properties for the ionomer alone. For example, anacid copolymer blended with organic acid(s) may be nominally neutralizedto a level of over 120% without losing melt processibility. Also,nominal neutralization over 120% reduces the volatility of the organicacids.

Alternatively, the acid copolymer(s) or unmodified, melt-processibleionomer(s) may be melt-blended with the organic acid(s) or salt(s) andother polymers in any manner known in the art. For example, a salt andpepper blend of the components may be made and then melt-blended in anextruder.

The melt-processible, acid copolymer/organic-acid-or-salt blend may betreated with the basic compound by methods known in the art, such asmelt-mixing. For example, a Werner & Pfleiderer twin-screw extruder maybe used to mix the acid copolymer and the organic acid and treat withthe basic compound at the same time. It is desirable that the mixing beconducted so that the components are intimately mixed, allowing thebasic compound to neutralize the acidic moieties.

The amount of base required to neutralize the acidic groups in the acidcopolymer and the organic acid(s) may be determined by stoichiometricprinciples. The amount of acid moieties in the acid copolymer andorganic acid(s) in the blend that is targeted for reaction with the baseis referred to herein as “% nominal neutralization” or “% nominallyneutralized”. Thus, sufficient basic compound is made available in theblend so that, in aggregate, the indicated level of nominalneutralization may be achieved. Of note are nominal neutralizationlevels of about 120% to about 150%, about 150% to about 180%, or about150% to about 200%.

Suitable basic compounds include compounds of alkali metals, such aslithium, sodium or potassium, transition metal ions and/or alkalineearth metal and mixtures or combinations of such cations. They includeformates, acetates, nitrates, hydrogencarbonates, carbonates, oxides,hydroxides or alkoxides of the ions of alkali metals, and formates,acetates, nitrates, oxides, hydroxides or alkoxides of the ions ofalkaline earth metals and transition metals. Basic compounds withmagnesium or calcium ions, such as the corresponding formate, acetate,hydroxide, oxide, alkoxide, etc., including magnesium hydroxide, are ofnote.

It is desirable to run the blending/neutralization process with anextruder equipped with a vacuum port to remove any excess volatilesincluding moisture. Moisture may have a negative impact on subsequentmolding operations in that excess moisture and volatiles may createunwanted foaming and voids in the molded article.

Of note is the composition wherein the overall salt of the composition(“overall salt” is a number of moles that is equal to the total numberof moles of carboxylate anions) comprises at least about 75 equivalent %magnesium counterions or calcium counterions. While other cations may bepresent, the equivalent percentage of magnesium salts or calcium saltsin the final blended ionomeric composition is preferably at least about75 equivalent %, more preferably at least about 80 equivalent %, andmost preferably at least about 90 equivalent % based on the total saltpresent in the blended composition.

The basic compound(s) may be added neat to the acid copolymer or ionomerthereof and the organic acid or salt thereof. The basic compound(s) mayalso be premixed with a polymeric material such as an acid copolymer, toform a “masterbatch” that may be added to the acid copolymer or ionomerthereof and the organic acid or salt thereof. A notable masterbatchcomprising about 40 to 60 weight % of a copolymer of ethylene, acrylicacid or methacrylic acid, and optionally an alkyl acrylate wherein thealkyl group has from 1 to 4 carbon atoms; and about 40 to 60 weight % ofa basic compound as described above (e.g., Mg(OH)₂). Also of note arecompositions comprising or prepared from master batches. A preferredcomposition comprising or prepared from a master batch includes

(1) about 30 to about 50 weight % of at least one aliphatic, unsaturatedorganic acid having from 16 to 22 carbon atoms;

(2) either (a) about 30 to about 60 weight % an ethylene acid copolymerconsisting essentially of ethylene and from 18 to 24 weight % ofcopolymerized comonomers of acrylic acid or methacrylic acid based onthe total weight of the ethylene acid copolymer, having a melt indexfrom about 200 to about 600 g/10 minutes;

-   -   or (b) about 30 to about 60 weight % an ethylene acid copolymer        consisting essentially of ethylene and from 18 to 24 weight % of        copolymerized comonomers of acrylic acid or methacrylic acid        based on the total weight of the ethylene acid copolymer, having        a melt index from about 50 to about 200 g/10 minutes;

(3) about 5 to about 15 weight % of a copolymer of ethylene, 5 to 10weight % of acrylic acid or methacrylic acid based on the total weightof the copolymer, and 15 to 30 weight % of an alkyl acrylate wherein thealkyl group has from 1 to 4 carbon atoms (such as butyl acrylate) basedon the total weight of the copolymer; wherein the amounts of (1) and (2)and (3) are based on the total weight of the composition; and

wherein the combined acid moieties of (1) and (2) and (3) are nominallyneutralized to a level from about 120% to about 200%.

Other Components

The compositions may additionally comprise small amounts of optionalmaterials including additives for use in polymeric materials. Examplesof suitable additives include, without limitation, plasticizers,stabilizers including viscosity stabilizers and hydrolytic stabilizers,primary and secondary antioxidants such as for example IRGANOX 1010,ultraviolet ray absorbers and stabilizers, anti-static agents, dyes,pigments or other coloring agents, fire-retardants, lubricants,processing aids, slip additives, antiblock agents such as silica ortalc, release agents, and/or mixtures thereof. Additional optionaladditives may include inorganic fillers as described below; acidcopolymer waxes, such as for example Honeywell wax AC540; TiO₂, which isused as a whitening agent; optical brighteners; surfactants; and othercomponents known in the art of golf ball manufacture to be useful butnot critical to golf ball performance and/or acceptance. Many suchadditives are described in the Kirk Othmer Encyclopedia of ChemicalTechnology, 5^(th) edition, John Wiley & Sons (Hoboken, 2005).

These additives may be present in the compositions in quantities thatmay be from 0.01 to 15 weight %, preferably from 0.01 to 10 weight %, orfrom 0.01 to 5 weight % of the total composition, so long as they do notdetract from the basic and novel characteristics of the composition anddo not significantly adversely affect the performance of the compositionor golf ball prepared from the composition.

The optional incorporation of such conventional ingredients into thecompositions may be carried out by any known process, for example, bydry blending, by extruding a mixture of the various constituents, by theconventional masterbatch technique, or the like.

Filler

Various optional fillers may be added to compositions to reduce cost, toaffect rheological, mixing and physical properties such as density, flexmodulus, hardness (e.g. Shore D), and/or melt flow index and the like,to increase or decrease weight, and/or to reinforce the material. Theamount of filler employed is primarily a function of weight requirementsand weight distribution of the golf ball. The fillers may be used toadjust the properties of a golf ball layer, reinforce the layer, or forany other purpose.

For example, the compositions may be reinforced by blending with a widerange of density-adjusting fillers, e.g., ceramics, glass spheres (solidor hollow, and filled or unfilled), and fibers, inorganic particles, andmetal particles, such as metal flakes, metallic powders, oxides, andderivatives thereof, as is known in the art.

Fillers may be used to modify the weight of the golf ball to meetrequired limits, by imparting additional density to compositions of thepreviously described components. Filler may be included in one or morelayers of the golf ball, such as the core or intermediate layer(s), theselection being dependent upon the type of golf ball desired (i.e.,two-piece, wound or multilayer), as more fully detailed below.

The filler may be inorganic, having a density from about 4 grams/cubiccentimeter (g/cc), or from about 5 g/cc, to about 10 g/cc or higher andmay be present in amounts between 0 and about 60 weight % based on thetotal weight of the composition. Examples of useful fillers includemetals such as titanium, tungsten, aluminum, bismuth, nickel,molybdenum, iron, steel, lead, copper, brass, boron, boron carbidewhiskers, bronze, cobalt, beryllium, zinc, tin, metal oxides includingzinc oxide, iron oxide, aluminum oxide, tin oxide, titanium oxide,magnesium oxide, zinc oxide and zirconium oxide, as well as other wellknown corresponding salts and oxides thereof. Other preferred fillersinclude barium sulfate, lead silicate, tungsten carbide, limestone(ground calcium/magnesium carbonate), zinc sulfate, calcium carbonate,zinc carbonate, barium carbonate, clay, tungsten, silicas, and mixturesof any of these. Preferably the filler material is non-reactive oralmost non-reactive. Of note are barium sulfate and tungsten powderfillers. Crystalline tungsten powder having a specific gravity of about19.3 g/cc is available from Alldyne Powder Technologies, Kulite TungstenCorporation or Buffalo Tungsten Incorporated.

Fillers may be employed in a finely divided form, for example, in a sizeless than about 20 mesh U.S. standard size, preferably from about 100mesh to about 1000 mesh, except for fibers and flock, which may beelongated. Flock and fiber sizes are desirably small enough tofacilitate processing. Filler particle size may depend upon desiredeffect, cost, ease of addition, and dusting considerations.

When filler is used in a particular composition, the coefficient ofrestitution (COR), as described below, will decrease approximatelyproportionally to the volumetric displacement of the polymer by thefiller. For example, if 5 volume % of filler is used to provide adesired specific gravity, then the COR of a sphere made from the filledcomposition may be about 95% of the COR of a comparable sphere made fromthe unfilled composition.

When tungsten is used as a filler with the compositions describedherein, the COR of a sphere of about 1.53 inches in diameter maydecrease about 0.015 to 0.020 compared to a sphere of the same sizeprepared from the corresponding unfilled composition, depending on theamount of tungsten that is present in the filled composition.Accordingly, thermoplastic compositions provided herein, when comprisinga filler, have a COR that is greater than 0.830, greater than 0.845, orgreater than 0.850.

Of note is a composition and a golf ball comprising or prepared from thecomposition wherein the composition comprises or is prepared from:

90 to 99.9 volume %, 95 to 99.9 volume %, or 97 to 99.9 volume % of ablend comprising

(1) about 30 to about 50 weight % of at least one aliphatic, unsaturatedorganic acid having from 16 to 22 carbon atoms;

(2) either (a) about 30 to about 60 weight % an ethylene acid copolymerconsisting essentially of ethylene and from 18 to 24 weight % ofcopolymerized comonomers of acrylic acid or methacrylic acid based onthe total weight of the ethylene acid copolymer, having a melt indexfrom about 200 to about 600 g/10 minutes;

-   -   or (b) about 30 to about 60 weight % an ethylene acid copolymer        consisting essentially of ethylene and from 18 to 24 weight % of        copolymerized comonomers of acrylic acid or methacrylic acid        based on the total weight of the ethylene acid copolymer, having        a melt index from about 50 to about 200 g/10 minutes;

(3) about 5 to about 15 weight % of a copolymer of ethylene, 5 to 10weight % of acrylic acid or methacrylic acid based on the total weightof the copolymer, and 15 to 30 weight % of an alkyl acrylate wherein thealkyl group has from 1 to 4 carbon atoms (such as butyl acrylate) basedon the total weight of the copolymer;

wherein the amounts of (1), (2) and (3) are based on the total weight ofthe blend and the combined acid moieties of (1) and (2) and (3) arenominally neutralized to a level from about 120% to about 200%;

and optionally 0.1 to 10, 0.1 to 5, or 0.1 to 3 volume % of filler.

Blowing or Foaming Agents

The compositions may be foamed by the addition of at least one physicalor chemical blowing or foaming agent or by blending with polymeric,ceramic, metal, and glass microspheres. The use of a foamed polymerallows the golf ball designer to adjust the density or mass distributionof the ball to adjust the angular moment of inertia, and thus, the spinrate and performance of the ball. Foamed materials also offer apotential cost savings due to the reduced use of polymeric material.

Useful blowing or foaming agents include but are not limited to organicblowing agents, such as azobisformamide; azobisisobutyronitrile;diazoaminobenzene; N,N-dimethyl-N,N-dinitroso terephthalamide;N,N-dinitrosopentamethylene-tetramine; benzenesulfonyl-hydrazide;benzene-1,3-disulfonyl hydrazide; diphenylsulfon-3-3, disulfonylhydrazide; 4,4′-oxybis benzene sulfonyl hydrazide; p-toluene sulfonylsemicarbizide; barium azodicarboxylate; butylamine nitrile; nitroureas;trihydrazino triazine; phenyl-methyl-uranthan; p-sulfonhydrazide;peroxides; and inorganic blowing agents such as ammonium bicarbonate andsodium bicarbonate. A gas, such as air, nitrogen, carbon dioxide, etc.,may also be injected into the composition during the injection moldingprocess.

A foamed composition may be formed by blending microspheres with thecomposition either during or before the molding process. Polymeric,ceramic, metal, and glass microspheres up to about 1000 micrometers indiameter are useful, and may be solid or hollow and filled or unfilled.

Of note is an article comprising a foamed composition, such as a ballcomprising a core or center prepared from the foamed composition. Inaddition to golf balls, such balls include baseballs and softballs.Either injection molding or compression molding may be used to form alayer or a core including a foamed polymeric material.

The compositions described herein may be injection molded or compressionmolded into various shaped articles, including cores or intermediatelayers for golf balls as described below. For example but notlimitation, injection molding conditions may include temperatures,pressures and cycle times as indicated in Table A.

TABLE A Injection Temperature Pressure Cycle Times (° C.) (mPa) (sec)Melt 160-260 Packing 25-180 Filling and Packing 40-90 Mold 10-30 Hold5-15 Hold 15-30 Front/Back Cooling Time 50-100 Screw Retraction 5-50

Golf Ball Construction

The compositions described herein may be used with any type of ballconstruction. Golf balls may be divided into two general classes: woundand solid. Wound golf balls may include a solid, hollow, or fluid-filledcenter or core, surrounded by windings of a tensioned elastomericthread-like material, and a cover. Since early wound balls had threeparts (center, windings and cover), wound balls also may be referred toas “three-piece” balls, even if additional layers are present. Solidgolf balls include one-piece, two-piece (i.e., solid core and a cover),and multilayer (i.e., a core of one or more layers, one or moreintermediate layers and/or a cover of one or more layers) golf balls. Asused herein, the term “solid golf ball” also includes a ball comprisinga hollow or fluid-filled center surrounded by one or more of solidlayers.

The golf ball may have an overall diameter of any size. United StatesGolf Association (“USGA”) specifications limit the minimum size of acompetition golf ball to 1.680 inches, but there is no specification ofmaximum diameter. Golf balls of any size, however, may be used forrecreational play. The diameter of the present golf balls may be from1.7 to about 1.95 inches, preferably from about 1.68 inches to about1.80 inches, more preferably from about 1.68 inches to about 1.76inches, and most preferably about 1.68 inches to about 1.74 inches.Preferably, the overall diameter of the core and all intermediate layersis about 80 percent to about 98 percent of the overall diameter of thefinished ball.

Golf balls usually have surface contouring to affect their aerodynamicperformance. The surface contouring may be embodied by a plurality ofsmall, shallow depressions (“dimples”) molded into the otherwisespherical surface of the golf ball. The use of various dimple patternsand profiles provides a relatively effective way to modify theaerodynamic characteristics of a golf ball. The dimples may be arrangedin any one of a number of patterns to modify the flight characteristicsof the balls. For example, the surface contouring of the golf ball maybe a conventional dimple pattern such as disclosed in U.S. Pat. No.6,213,898, an icosahedron-based pattern such as described in U.S. Pat.No. 4,560,168, or an octahedral-based dimple pattern as described inU.S. Pat. No. 4,960,281. Examples of dimple patterns include thefollowing.

The golf ball may have an icosahedron dimple pattern that includes 20triangles made from about 362 dimples and, except perhaps for the moldparting line, does not have a great circle that does not intersect anydimples. Each of the large triangles, preferably, has an odd number ofdimples (7) along each side and the small triangles have an even numberof dimples (4) along each side. To properly pack the dimples, the largetriangle has nine more dimples than the small triangle. The ball mayhave five different sizes of dimples in total. The sides of the largetriangle may have four different sizes of dimples and the smalltriangles have two different sizes of dimples.

The golf ball may have an icosahedron dimple pattern with a largetriangle including three different dimples and the small triangleshaving only one diameter of dimple. There may be 392 dimples and onegreat circle that does not intersect any dimples. More than fivealternative dimple diameters may be used.

The golf ball may have an octahedron dimple pattern including eighttriangles made from about 440 dimples and three great circles that donot intersect any dimples. In the octahedron pattern, the patternincludes a third set of dimples formed in a smallest triangle inside ofand adjacent to the small triangle. To properly pack the dimples, thelarge triangle has nine more dimples than the small triangle and thesmall triangle has nine more dimples than the smallest triangle. Theball has six different dimple diameters distributed over the surface ofthe ball. The large triangle has five different dimple diameters, thesmall triangle has three different dimple diameters and the smallesttriangle has two different dimple diameters.

Alternatively, the dimple pattern may be arranged according tophyllotactic patterns, such as described in U.S. Pat. No.6,338,684.Dimple patterns may also be based on Archimedean patterns including atruncated octahedron, a great rhombcuboctahedron, a truncateddodecahedron, and a great rhombicosidodecahedron, wherein the patternhas a non-linear parting line, as disclosed in U.S. application Ser. No.10/078,417. Another dimple pattern, consisting of a plurality of dimplesof various sizes for providing an optimum impact at the moment ofhitting the golf ball, is disclosed in US Patent Appln. Publn. No.2006/0276267. The golf balls may also be covered with non-circularamorphous shaped dimples, as disclosed in U.S. Pat. No. 6,409,615.

Dimple patterns that provide a high percentage of surface coverage arepreferred, and are well known in the art. For example, U.S. Pat. Nos.5,562,552, 5,575,477, 5,957,787, 5,249,804, and 4,925,193 disclosegeometric patterns for positioning dimples on a golf ball. The golfballs may have a dimple coverage of the surface area of the cover of atleast about 60 percent, or at least about 65 percent, or at least 70percent or greater. Dimple patterns having even higher dimple coveragevalues may also be used. Thus, the golf balls may have dimple coverageof at least about 75 percent or greater, about 80 percent or greater, oreven about 85 percent or greater.

Several additional non-limiting examples of dimple patterns with varyingsizes of dimples are also provided in U.S. patent application Ser. No.09/404,164 and U.S. Pat. No. 6,213,898.

The total number of dimples on the ball, or dimple count, may varydepending on such factors as the sizes of the dimples and the patternselected. The total number of dimples on the ball may be between about100 to about 1000 dimples, although one skilled in the art wouldrecognize that differing dimple counts within this range maysignificantly alter the flight performance of the ball. For example, thedimple count may be about 380 dimples or greater, or about 400 dimplesor greater, or about 420 dimples or greater, such as about 422 dimples.In some cases, it may be desirable to have fewer dimples on the ball,for example a dimple count of about 380 dimples or less or about 350dimples or less.

Dimple profiles revolving a catenary curve about its symmetrical axismay increase aerodynamic efficiency, provide a convenient way to alterthe dimples to adjust ball performance without changing the dimplepattern, and result in uniformly increased flight distance for golfersof all swing speeds. Thus, catenary curve dimple profiles, as disclosedin U.S. patent application Ser. No. 09/989,191 may be used.

Alternatively, the surface contouring of the golf ball may have anon-dimple pattern such as a tubular lattice pattern, such as the onedisclosed in U.S. Pat. No. 6,290,615.

Any surface contouring or dimple pattern is contemplated for the golfballs described herein and is not limited to the dimple patternsdisclosed in these references.

Most golf balls comprise concentric layers of materials in theirconstruction. Golf balls wherein at least one layer of the golf ballcomprises the composition described herein are contemplated. Forexample, the composition may be used in cores or centers of two-piece,wound, and multilayer golf ball designs, including golf balls havingdouble cores (a core comprising two parts or layers such as an innercore and an outer core), intermediate layer(s), and/or double covers (acover comprising two parts or layers such as an inner cover and an outercover). As known to those of ordinary skill in the art, the type of golfball constructed, i.e., double core, double cover, and the like, dependson the type of performance desired of the ball. As used herein, the term“layer” includes any substantially spherical or spherically symmetricalportion of a golf ball, i.e., a core or center, an intermediate layer,and/or a cover. As used herein, the term “inner layer” refers to anygolf ball layer beneath the outermost structural layer of the golf ball.The ball may be coated, e.g. with a urethane lacquer, painted orotherwise finished for appearance purposes, but such a coating, paintingand/or finishing generally does not have a significant effect on theperformance characteristics of the ball. Therefore, coatings, paintlayers, top coats, finishes or the like applied to the surface or coverof a golf ball are not within the meaning of the term “layer” or“structural layer” as used herein. As used herein, the term “multilayer”without specifying a number refers to a golf ball with at least threestructural layers comprising a core, intermediate layer and cover.

The outermost structural layer of a golf ball is known as the cover, andit provides the interface between the ball and a club. Properties thatare desirable for the cover are good moldability, high abrasionresistance, high tear strength, high resilience, and good mold release,among others.

Covers may be made from any conventional golf ball cover material suchas ionomer resin, balata rubber or thermoset/thermoplastic polyurethanesand the like and include the surface contouring or dimple pattern. Thecovers may be made by injection or compression molding a covercomposition over a thermoplastic or thermoset core for a two-piece golfball, over windings around a thermoplastic or thermoset center for awound golf ball, or as the outermost layer of a multilayer golf ball.

The cover has a thickness to provide sufficient strength, goodperformance characteristics, and durability. For example, cover layersmay be from about 0.005 inch to about 0.35 inch in thickness, or fromabout 0.02 inches to about 0.35 inches. The cover may have a thicknessof about 0.02 inches to about 0.12 inches, or about 0.1 inches or less.An outer cover layer may have a thickness from about 0.02 inches toabout 0.07 inches or about 0.05 inches or less, such as about 0.02inches to about 0.05 inches, about 0.02 inches to about 0.045 inches,about 0.025 to about 0.04 inches, or about 0.03 inches thick.

Prepolymers used for polyurethane covers are produced by combining atleast one polyol, such as a polyether, polycaprolactone, polycarbonateor a polyester, and at least one isocyanate. Thermoset polyurethanes areobtained by curing at least one polyurethane prepolymer with a curingagent selected from a polyamine, triol or tetraol. Thermoplasticpolyurethanes are obtained by curing at least one polyurethaneprepolymer with a diol curing agent. The choice of the curatives may beimportant because some urethane elastomers that are cured with a dioland/or blends of diols may not produce urethane elastomers with theimpact resistance desired in a golf ball cover.

Blending polyamine curatives with diol-cured urethane elastomericformulations may provide thermoset urethanes with improved impact andcut resistance.

As discussed elsewhere herein, the cover composition may be molded ontothe golf ball in any known manner, such as by casting, compressionmolding, injection molding, reaction injection molding, or the like. Oneskilled in the art would appreciate that the molding method used may bedetermined at least partially by the properties of the composition. Forexample, casting may be preferred when the material is thermoset,whereas compression molding or injection molding may be preferred forthermoplastic compositions.

The innermost layer of the golf ball is known as the center or core. Thecore may be solid, semi-solid, hollow, filled with a fluid, such as agas or liquid, powder-filled, or have a metal layer. It may be aone-piece or multi-component core. The term “semi-solid” as used hereinrefers to a paste, a gel, or the like. Any core material known to one ofordinary skill in that art is suitable for use in the golf balls of theinvention. Suitable core materials include thermoset materials, such asrubber, styrene butadiene, polybutadiene, isoprene, polyisoprene,trans-isoprene, and thermoplastics such as ionomer resins, polyamides orpolyesters, and thermoplastic and thermoset polyurethane or polyureaelastomers. Preferably, the core may be prepared from a composition asdescribed herein.

A solid core is prepared from a composition that is injection-molded orcompression-molded into a substantially spherical or sphericallysymmetrical solid. Cores may be spherical or they may have a morecomplex spherically symmetrical shape (for example, comprising a centralportion and a plurality of projections and/or depressions). For examplebut not limitation, cores with complex shapes are disclosed in US PatentApplication Publication No. 2004/0209705. The core may be surfacetreated by plasma treatment, corona discharge, chemical treatment ormechanically treated.

The core has an average diameter such that the thickness of the coverand any additional layers may be added to the diameter of the core toprovide a golf ball of desired size, for example, at least about 1.68inches in diameter. The core of the golf ball may also be extremelylarge in relation to the rest of the ball. For example, the core maymake up about 90% to about 98% of the ball, or about 94% to about 96% ofthe ball. The diameter of the core may be about 1.54 inches or greater,about 1.55 inches or greater, about 1.59 inches or greater, or about1.64 inches or less. The core may have an average diameter from about0.09 inches to about 1.65 inches, about 1.2 inches to about 1.630inches, about 1.3 inches to about 1.6 inches, about 1.39 inches to about1.6 inches, about 1.5 inches to about 1.6 inches, or about 1.55 inchesto about 1.65 inches.

When the core includes an inner core layer and an outer core layer, theinner core layer may be preferably about 0.9 inches or greater and theouter core layer preferably has a thickness of about 0.1 inches orgreater. The inner core layer may have a diameter from about 0.09 inchesto about 1.2 inches and the outer core layer may have a thickness fromabout 0.1 inches to about 0.8 inches. The inner core layer diameter maybe from about 0.095 inches to about 1.1 inches and the outer core layermay have a thickness of about 0.20 inches to about 0.03 inches.

Conventional core materials may include a base rubber, including naturalor synthetic rubbers, a crosslinking agent, a filler, and aco-crosslinking or initiator agent. An example base rubber is1,4-polybutadiene having a cis-structure of at least 40%. Preferably,the base rubber comprises high-Mooney-viscosity rubber. If desired, thepolybutadiene may also be mixed with other elastomers known in the artsuch as natural rubber, polyisoprene rubber and/or styrene-butadienerubber in order to modify the properties of the core. The crosslinkingagent may include a metal salt of an unsaturated fatty acid such as azinc salt or a magnesium salt of an unsaturated fatty acid having 3 to 8carbon atoms such as acrylic or methacrylic acid. Suitable crosslinkingagents include metal salt diacrylates, dimethacrylates andmonomethacrylates wherein the metal is magnesium, calcium, zinc,aluminum, sodium, lithium or nickel. The crosslinking agent may bepresent in an amount from about 15 to about 30 parts per hundred of therubber, preferably from about 19 to about 25 parts per hundred of therubber and most preferably about 20 to 24 parts crosslinking agent perhundred of rubber. The core compositions may also include at least oneorganic or inorganic cis-trans catalyst to convert a portion of thecis-isomer of polybutadiene to the trans-isomer, as desired. Theinitiator agent may be any known polymerization initiator whichdecomposes during the cure cycle. Suitable initiators include peroxidecompounds such as dicumyl peroxide,1,1-di-(t-butylperoxy)-3,3,5-trimethyl cyclohexane, α-αbis-(t-butylperoxy)-diisopropylbenzene, 2,5-dimethyl-2,5di-(t-butylperoxy)hexane or di-t-butyl peroxide and mixtures thereof.

Intermediate layers between the cover and the core also may be known as“mantles,” “inner covers,” “outer cores” “envelope layers” or “boundarylayers.” These intermediate layers may form a substantially spherical orspherically symmetrical shell around the core. For example, intermediatelayers may have a plurality of projections and/or depressions that arecomplementary to any projections and/or depressions in the other layersof the golf ball, such as in the outer surface of the core and/or theinner face of the cover. “Mantle” or “boundary layer” may refer to arelatively thin layer, for example, from about 0.20 inch to about 0.075inch in thickness, in contact with the inner face of the cover layer.

The intermediate layer may comprise ionomeric materials and/ornon-ionomeric materials such as polyvinyl chloride, copolymers of vinylchloride with vinyl acetate, acrylic esters or vinylidene chloride,polyolefins such as polyethylene, polypropylene, polybutylene copolymersand homopolymers produced using a single-site catalyst or a metallocenecatalyst, polyphenylene ether, copolymers such as ethylenemethylacrylate, ethylene ethylacrylate, ethylene vinyl acetate, ethylenemethacrylic acid, ethylene acrylic acid, propylene acrylic acid,polyamides such as poly(hexamethylene adipamide) and others made fromdiamines and dibasic acids, and those from amino acids such aspoly(caprolactam) and mixtures of any of the above, includingpolyamide/ionomer blends, polyphenylene ether/ionomer blends, etc. Othersuitable materials include but are not limited to, thermoplastic orthermosetting polyurethanes, thermoplastic block polyesters, forexample, a polyester elastomer such as that marketed by E.I. du Pont deNemours & Co. of Wilmington, Del. (“DuPont”) under the brand HYTREL, orthermoplastic block polyamides, for example, a polyether amide such asthat marketed by Arkema S. A. of Paris, France, under the brand namePEBAX, a blend of two or more non-ionomeric thermoplastic elastomers, ora blend of one or more ionomers and one or more non-ionomericthermoplastic elastomers. These materials may be blended with ionomersin order to reduce cost relative to the use of higher quantities ofionomer. Preferably, a mantle or intermediate layer may be prepared froma composition described herein.

The ionomer used in intermediate layers may include either so-called“low acid” and “high acid” ionomers of ethylene acid copolymers, as wellas blends thereof. In general, ionomers prepared by neutralizing acidcopolymers including up to about 15% of copolymerized acid residuesbased on the total weight of the unneutralized ethylene acid copolymer,are considered “low acid” ionomers, while those including greater thanabout 15% acid are considered “high acid” ionomers.

A low acid ionomer is believed to impart high spin. Thus, theintermediate layer may include a low acid ionomer where the acid ispresent in about 10 to 15 weight % and optionally includes acopolymerized softening comonomer, e.g., iso- or n-butylacrylate, toproduce a softer terpolymer.

For low spin rate and maximum distance, the intermediate layer mayinclude at least one high acid ionomer. In these high modulus ionomers,the acrylic or methacrylic acid is present in about 15 to about 35weight %, such as about 16 weight %, or about 17 to about 25 weight %,or about 18.5 percent to about 21.5 weight % of a copolymerizedcarboxylic acid. An additional copolymerized comonomer may also beincluded to produce a softer terpolymer.

In either low acid ionomers or high acid ionomers, an additionalcomonomer may be selected from the group consisting of vinyl esters ofaliphatic carboxylic acids wherein the acids have 2 to 10 carbon atoms,vinyl ethers wherein the alkyl groups contains 1 to 10 carbon atoms, andalkyl acrylates or methacrylates wherein the alkyl group contains 1 to10 carbon atoms. Suitable softening comonomers include vinyl acetate,acrylate esters such as iso- or n-butylacrylate, methyl acrylate, methylmethacrylate, ethyl acrylate, ethyl methacrylate, butyl methacrylate, orthe like.

Consequently, examples of a number of copolymers suitable for use toproduce the high modulus ionomers include, but are not limited to, highacid embodiments of an ethylene/acrylic acid copolymer, anethylene/methacrylic acid copolymer, an ethylene/itaconic acidcopolymer, an ethylene/maleic acid copolymer, an ethylene/methacrylicacid/vinyl acetate copolymer, an ethylene/acrylic acid/vinyl alcoholcopolymer, and the like.

The intermediate layer may also be formed of a binding material and aninterstitial material distributed in the binding material, wherein theeffective material properties of the intermediate layer are uniquelydifferent for applied forces normal to the surface of the ball fromapplied forces tangential to the surface of the ball. Examples of thistype of intermediate layer are disclosed in U.S. patent application Ser.No. 10/028,826. The interstitial material may extend from theintermediate layer into the core, or it may be embedded in the cover, orbe in contact with the inner surface of the cover, or be embedded onlyin the cover.

At least one intermediate layer may also be a moisture barrier layer,such as the ones described in U.S. Pat. No. 5,820,488. The moisturebarrier layer may be any suitable material having a lower water vaportransmission rate than the other layers between the core and the outersurface of the ball, i.e., cover, primer, and clear coat. The moisturebarrier layer may have a water vapor transmission rate (MVTR) that issufficiently low to reduce the loss of COR of the golf ball by at least5% if the ball is stored at 100° F. and 70% relative humidity for sixweeks as compared to the loss in COR of a golf ball that does notinclude the moisture barrier, has the same type of core and cover, andis stored under substantially identical conditions. For example, thematerial for the moisture barrier layer may have MVTR of less than 100(mil·gm)/(m²·day) when measured according to ASTM F1249 at 100% RH andaround 38° C.

Alternatively, the moisture barrier layer may be prepared from amaterial having a weight gain of less than 2.0%, preferably less than orequal to 1.6% weight gain, more preferably less than or equal to 1.3%weight gain, or less than or equal to 1.2% weight gain, or less than orequal to 1.0% weight gain, or less than or equal to 0.8% weight gain,and or less than or equal to 0.55% weight gain, after exposure to 50%relative humidity (RH) for 90 days at room temperature (about 20-25°C.).

The range of thickness for an intermediate layer of a golf ball is largebecause of the many possibilities when using an intermediate layer,i.e., as an outer core layer, an inner cover layer, a wound layer, amoisture/vapor barrier layer. When used in a golf ball of the invention,the intermediate layer, or inner cover layer, may have a thickness about0.3 inches or less. The thickness of the intermediate layer may be fromabout 0.002 inches to about 0.1 inches, preferably about 0.01 inches orgreater. The thickness of the intermediate layer may be about 0.09inches or less, preferably about 0.06 inches or less. The intermediatelayer thickness may be about 0.05 inches or less, more preferably about0.01 inches to about 0.045 inches. Alternatively, the intermediate layerthickness is about 0.02 inches to about 0.04 inches, or from about 0.025inches to about 0.035 inches, or about 0.035 inches thick, or from about0.03 inches to about 0.035 inches thick. Varying combinations of theseranges of thickness for the intermediate and outer cover layers may beused in combination with other embodiments described herein.

The ratio of the thickness of an intermediate layer to the cover layermay be about 10 or less, or about 3 or less, or about 1 or less. Thecore and intermediate layer(s) together form an inner ball preferablyhaving a diameter of about 1.48 inches or greater, or about 1.52 inchesor greater for a 1.68-inch ball. The inner ball of a 1.68-inch ball mayhave a diameter of about 1.66 inches or less. A 1.72-inch (or more) ballmay have an inner ball diameter of about 1.50 inches or greater, orabout 1.70 inches or less.

The golf balls may also have a plurality of pyramidal projectionsdisposed on the intermediate layer, as disclosed in U.S. Pat. No.6,383,092, which may cover between about 20 percent to about 80 of thesurface of the intermediate layer. The golf ball may have a non-planarparting line allowing for some of the plurality of pyramidal projectionsto be disposed about the equator. Such a golf ball may be made using amold disclosed in U.S. patent application Ser. No. 09/442,845, whichallows for greater uniformity of the pyramidal projections.

Of note is a golf ball comprising a cover prepared from a polyurethaneor polyurea composition; and a core or intermediate layer prepared fromthe composition as described herein. Also of note is a golf ballcomprising a cover prepared from an ionomer composition; and a core orintermediate layer prepared from the composition as described herein.

Two-Piece Golf Ball Preferred Embodiments

Two-piece balls are manufactured by well-known techniques wherein coversare injection or compression molded over cores. The core of a two-pieceball is made by injection or compression molding a substantiallyspherical or spherically symmetrical solid of desired size and shapefrom the thermoplastic composition described herein that is optionallyfilled with sufficient filler to provide a desired core density.Desirable core density may be, for example, from about 1.14 g/cc toabout 1.2 g/cc, depending on the diameter of the core and the thicknessand composition of the cover to produce a golf ball meeting the weightlimits (45 grams) set by the PGA.

Of note is a golf ball comprising a cover prepared from a polyurethaneor polyurea composition; and a core prepared from the composition asdescribed herein. Also of note is a golf ball comprising a coverprepared from an ionomer composition; and a core prepared from thecomposition as described herein.

Wound Golf Ball Preferred Embodiments

Wound balls are manufactured by well known techniques as described in,e.g., U.S. Pat. No. 4,846,910. The center or core of wound balls is madeby injection or compression molding a solid (optionally semi-solid,hollow, fluid-filled, or powder-filled) of desired size and shape from athermoplastic composition described above that is optionally filled withsufficient filler to provide a desired center density depending on thediameter of the center, the windings, and the thickness and compositionof the cover to produce a golf ball meeting USGA weight limits. The sizeand shape of the center is such that it can be wound with elastomericmaterial. The windings may be any elastomeric material conventionallyused in wound golf balls and are wound around the center. Covers arethen injection or compression molded over the windings. Intermediatelayers may be used between the windings and the cover layer.

The tensioned elastomeric material may include a polybutadiene reactionproduct discussed above. It may also be formed from conventionalpolyisoprene, or a polyurea composition. Solvent spun polyetherurea, asdisclosed in U.S. Pat. No. 6,149,535, may be used to form the tensionedelastomeric material, which may be useful in achieving a smallercross-sectional area with multiple strands. The tensioned elastomericlayer may be a high tensile filament having a tensile modulus of about10,000 kpsi or greater, as disclosed in U.S. patent application Ser. No.09/842,829. The tensioned elastomeric layer may be coated with a bindingmaterial that will adhere to the core and itself when activated, causingthe strands of the tensioned elastomeric layer to swell and increase thecross-sectional area of the layer by at least about 5 percent, as inU.S. patent application Ser. No. 09/841,910.

Of note is a wound golf ball having a cover comprising or prepared froma polyurethane or polyurea composition; and a core or intermediate layerprepared from the composition as described herein. Also of note is awound golf ball having a cover comprising an ionomer or prepared from anionomer composition; and a core or intermediate layer prepared from thecomposition as described herein.

Multilaver Golf Ball Preferred Embodiments

Multilayer golf balls have in addition to the cover and the core, atleast one additional layer between the cover and the core, also known asmantles or intermediate layers. Multilayer balls are manufactured bywell-known techniques wherein an injection or compression molded core iscovered by one or more intermediate layers or mantles and a cover byinjection or compression molding. The various layers of a ball, (thatis, the core, the mantle(s), and/or intermediate layers) are made byinjection or compression molding a sphere or layer of desired size orthickness from a thermoplastic composition described herein which isoptionally filled with sufficient filler to provide a golf ball meetingany desired or required weight limits. The amount of filler in the coreand/or mantle(s) may be varied from 0 to about 60 weight % depending onthe size (thickness) of the components and the desired location of theweight in the ball. Preferably, enough filler is used so that the ballhas an overall density of 1.14 gm/cc. The filler may be used in the coreand not in the mantle, in the mantle and not in the core, or in both.While not intending to be limiting as to possible combinations, examplesinclude:

-   -   1. a core comprising the composition as described herein, with        or without filler adjusted to provide a golf ball of the desired        weight, with a cover made of any composition known in the art to        be useful as a cover;    -   2. a core comprising the composition as described herein, with        or without filler adjusted to provide a golf ball of the desired        weight, used in a multilayer golf ball core with at least one        mantle, with or without filler adjusted to provide a golf ball        of the desired weight, and a cover made of any composition known        in the art to be useful as a cover;    -   3. a core made of any composition (including thermoset        compositions such as polybutadiene rubber), with or without        filler provided that the weight of the finished golf ball meets        the required limit with an intermediate layer comprising the        composition as described herein, with or without filler provided        that the weight of the finished golf ball meets the required        limit.

Of note is a golf ball comprising a cover prepared from a polyurethanecomposition; and a core prepared from the composition as describedherein, further comprising at least one additional intermediate layer.Also of note is a golf ball comprising a cover prepared from an ionomercomposition; and a core prepared from the composition as describedherein, further comprising at least one additional intermediate layer.Also of note is a golf ball comprising a cover prepared from apolyurethane composition; and a core, further comprising at least oneadditional intermediate layer prepared from the composition as describedherein. Also of note is a golf ball comprising a cover prepared from anionomer composition; and a core, further comprising at least oneadditional intermediate layer prepared from the composition as describedherein.

After molding, the golf balls produced may undergo various furtherprocessing steps such as buffing, painting, coating, surface treatingand marking for further benefits, such as disclosed in U.S. Pat. No.4,911,451. Protective and decorative coating materials, as well asmethods of applying such materials to the surface of a golf ball coverare well known in the golf ball art. Such coating materials compriseurethanes, urethane hybrids, epoxies, polyesters and acrylics. Ifdesired, more than one coating layer may be used. The coating layer(s)may be applied by any suitable method known to those of ordinary skillin the art, such as an in-mold coating process, as described in U.S.Pat. No. 5,849,168.

The conventional technique for highlighting whiteness is to form a covertoned white with titanium dioxide, subjecting the cover to such surfacetreatment as corona treatment, plasma treatment, UV treatment, flametreatment, or electron beam treatment, and applying one or more layersof clear paint, which may contain a fluorescent whitening agent.

Golf ball covers frequently contain a fluorescent material and/or a dyeor pigment to achieve the desired color characteristics. A golf ball mayalso be treated with a base resin paint composition as disclosed in U.S.Patent Publication No. 2002/0082358, which includes a derivative of7-triazinylamino-3-phenylcoumarin as the fluorescent whitening agent toprovide improved weather resistance and brightness.

In addition, trademarks or other indicia may be stamped, i.e.,pad-printed, on the outer surface of the ball cover, and the stampedouter surface treated with at least one clear coat to give the ball aglossy finish and protect the indicia stamped on the cover. The golfballs may also be subjected to dye sublimation, wherein at least onegolf ball component is subjected to at least one sublimating ink thatmigrates at a depth into the outer surface and forms an indicia. Thesublimating ink may includes at least one of an azo dye, anitroarylamine dye, or an anthraquinone dye as described in U.S. patentapplication Ser. No.10/012,538.

Laser marking of a selected surface portion of a golf ball causing thelaser light-irradiated portion to change color is also contemplated, asdisclosed in U.S. Pat. Nos. 5,248,878 and 6,075,223. In addition, thegolf balls may be subjected to ablation, i.e., directing a beam of laserradiation onto a portion of the cover, irradiating the cover portion,wherein the irradiated cover portion is ablated to form a detectablemark, wherein no significant discoloration of the cover portion resultstherefrom. Ablation is discussed in U.S. patent application Ser. No.09/739,469.

Selection of Materials for Performance Criteria

Properties such as hardness, modulus, compression, resilience, corediameter, intermediate layer thickness and cover thickness of golf ballshave been found to affect play characteristics such as spin, initialvelocity and feel of golf balls.

Depending on the construction and desired characteristics of the golfball, the core, intermediate layers, and cover may have differentresilience, compression or hardness to achieve desired performancecharacteristics. The compositions described herein may be useful inpreparing golf balls with resilience, compression, modulus or hardnessgradients within a golf ball.

Initial Velocity and COR

The compositions described herein provide tailored resiliency asindicated by the coefficient of restitution (COR). Coefficient ofrestitution (COR₁₂₅) may be measured by firing a sphere that is 1.50 to1.68 inches in diameter at an initial velocity of 125 feet/secondagainst a steel plate positioned 3 feet from the point where initialvelocity is determined and dividing the velocity of rebound from theplate by the initial velocity. One may also measure COR at severalinitial velocities, develop a correlation and determine a COR at aspecified initial velocity based on the correlation. COR may bedetermined on a sphere prepared from a single composition or a spherehaving two or more layers (for example, a finished golf ball). Oneskilled in the art will recognize that COR cannot be greater than 1.0.

The compositions described herein are highly resilient, that is, theyexhibit high COR values. For spheres prepared from the compositionwithout filler, the compositions provide COR measurements from about0.860 or about 0.870 to about 0.90 or higher when measured according tothe COR Method described herein. Any COR value within that range may beconsidered as “high COR”. As indicated above, the presence of fillerreduces the COR roughly proportional to the reduction in volume of theresin fraction of the volume of a test sphere. Compositions describedherein, when containing filler, have COR of greater than about 0.83, forexample from about 0.830 or about 0.845 or about 0.850 to about 0.86, orhigher.

The USGA assesses resiliency by striking a sphere with a mechanical headand determining the ball's initial velocity as it passes through twolight beams. The USGA has no current limit on the COR of a golf ball,but requires that the initial velocity of the golf ball cannot exceed250±5 feet/second (ft/s). Thus, the initial velocity of the golf ballmay be about 245 ft/s or greater, or about 250 ft/s or greater, or about255 ft/s or greater. The initial velocity may be about 253 ft/s to about254 ft/s, or about 255 ft/s.

While the current rules on initial velocity require that golf ballmanufacturers stay within the USGA limits when producing golf balls foruse in official events, one of ordinary skill in the art wouldappreciate that the golf balls described herein may provide an initialvelocity outside of the USGA's prescribed range. As is discussed above,however, noncompliant golf balls may have value in purely recreationalplay.

As a result of the USGA's initial velocity limitation, a goal is tomaximize COR without violating the 255 ft/s limit. For a solid testsphere prepared from a single composition, the COR will depend on avariety of characteristics of the composition, including its hardness.COR will generally increase as hardness is increased. In a two-piecesolid golf ball with a core and a cover, one of the purposes of thecover is to produce a gain in COR over that of the core. When thecontribution of the core to high COR is substantial, a lessercontribution is required from the cover. Similarly, when the covercontributes substantially to high COR of the ball, a lesser contributionis needed from the core.

Compression

The terms “compression” or “PGA Compression” used in the golf ball artdefine the overall resistance to deflection that a golf ball undergoeswhen subjected to a compressive load. Compression indicates the amountof resistance to change in a golf ball's shape upon striking. It may bemeasured on a finished ball or on a test piece prepared from thecomposition of interest. PGA compression is based on a unitless scalefrom 0 to 200. Each 1-point drop in PGA compression from 200 representsa change of 0.001 inch in deflection when a standard force (200 pounds)is applied to the external surface of the ball. For example, a ball thatexhibits no deflection (0.0 inches in defection) is rated 200, a ballthat defects 0.1 inches rated 100 and a ball that deflects 0.110 inchesis rated 90 and a ball that deflects 0.2 inches is rated 0. The lowerthe PGA compression value, the softer the feel of the ball uponstriking.

PGA compression may be determined by an apparatus fashioned in the formof a small press with an upper and lower anvil. A ball is placed betweenan upper anvil at rest against a 200-pound die spring, and a lower anvilis movable by means of a crank mechanism. As the lower anvil is raisedby the crank, it compresses the ball against the upper anvil, the ballthen loading the upper anvil that in turn loads the spring. Theequilibrium point of the upper anvil is measured by a dial micrometer ifthe anvil is deflected by the ball more than 0.100 inches (lessdeflection is regarded as zero compression) and the reading on themicrometer dial is referred to as the compression of the ball. Anexample compression tester is produced by OK Automation, Sinking Spring,Pa. (formerly, Atti Engineering Corporation of Newark, N.J.). Thismachine, equipped with a Federal Dial Gauge, Model D81-C, employs acalibrated spring under a known load. Compression measured with thisinstrument may be referred to as “Atti compression” and corresponds to“PGA compression.”

Other methods of measuring compression are known and compression valuesfrom those methods may generally be correlated to PGA compression byknown algorithms.

A modified Riehle Compression Machine originally produced by RiehleBros. Testing Machine Company, Philadelphia, Pa., may be used toevaluate compression of the various components (i.e., cores, mantles,covers, finished balls, etc.) of the golf balls. The Riehle compressiondevice determines deformation in thousandths of an inch under a loaddesigned to emulate the 200 pound spring constant of the Atti or PGAcompression tester. Atti or PGA compression may be approximately relatedto Riehle compression by the following equation:

Atti or PGA compression=(160−Riehle Compression). Thus, a Riehlecompression of 100 would be the same as an Atti compression of 60.

Other compression devices may also be used to measure golf ballcompression, such as a Whitney Tester, Whitney Systems, Inc.,Chelmsford, Mass., or an Instron Device, Instron Corporation, Canton,Mass. These devices are designed to correlate or correspond to PGA orAtti compression through a set relationship or formula. Compression of agolf ball, core, or golf ball component using an INSTRON Device (model5544) is measured to be the deflection (in inches) caused by a 200 poundload applied in a Load Control Mode at the rate of 15 kips (15×10³lbf/sec), an approach speed of 20 inches per minute, with a preload of0.2 lbf plus the system compliance of the device. Compression valuesdetermined using an INSTRON device may range from about 0.1 to about0.2.

The combination of resilience and compression for a golf ball may besummarized by the “Nes Factor,” which is determined by taking the sum ofthe compression measured by an INSTRON device and resilience (COR)measurements and multiplying this value by 1000. It represents anoptimal combination of softer but more resilient compositions.

Another measure of resilience is the “loss tangent,” or tan Δ, which isobtained when measuring the dynamic stiffness of an object. Loss tangentand terminology relating to such dynamic properties is typicallydescribed according to ASTM D4092-90. Thus, a lower loss tangentindicates a higher resiliency, thereby indicating a higher reboundcapacity. Low loss tangent indicates that most of the energy imparted toa golf ball from the club is converted to dynamic energy, i.e., launchvelocity and resulting longer distance. The rigidity or compressivestiffness of a golf ball may be measured, for example, by its dynamicstiffness. Higher dynamic stiffness indicates a higher compressivestiffness. For golf balls with desirable compressive stiffness, thedynamic stiffness of the material should be less than about 50,000 N/mat −50° C., for example, between about 10,000 and 40,000 N/m at −50° C.,or between about 20,000 and 30,000 N/m at −50° C.

Hardness

The ratio of cover hardness to inner ball hardness may be a primaryvariable used to control the aerodynamics of a ball and, in particular,the spin of a ball. In general, the harder the inner ball, the greaterthe driver spin and the softer the cover, the greater the driver spin.

For example, the intermediate layer may be intended to be the hardeststructure in the ball. When the outer cover layer is softer than theintermediate layer or inner cover layer, the ratio of the Shore Dhardness of the outer cover material to that of the intermediate layermaterial may be about 0.8 or less, or about 0.75 or less, or about 0.7or less, or about 0.5 or less, or about 0.45 or less. When the hardnessdifferential between the cover layer and the intermediate layer is notintended to be as significant, the cover may have a hardness of about 55Shore D to about 65 Shore D, and the ratio of the Shore D hardness ofthe outer cover to the intermediate layer is about 1.0 or less, or about0.9 or less. When the cover layer is harder than the intermediate layer,the ratio of the Shore D hardness of the cover layer to that of theintermediate layer may be about 1.0 to about 1.33, or about 1.0 to about1.14.

When a two-piece ball is constructed, the core may be softer than thecover. For example, the core hardness may range from about 30 Shore D toabout 50 Shore D, and the cover hardness may be from about 50 Shore D toabout 80 Shore D. The ratio between the cover hardness and the corehardness may be about 1.75 or less, or about 1.55 or less.

One of ordinary skill in the art understands that there is a fundamentaldifference between “material hardness” and “hardness, as measureddirectly on a golf ball.” Material hardness is defined by the procedureset forth in ASTM-D2240 and involves measuring the hardness of a flatplaque formed of the material for which the hardness is to be measured.Hardness when measured directly on a golf ball or other sphericalsurface is a completely different measurement and results in a differenthardness value. This difference results from a number of factorsincluding, but not limited to, ball construction (i.e., core type,number of core and/or cover layers, etc.), ball (or sphere) diameter,and the material composition of adjacent layers. It should also beunderstood that the two measurement techniques are not linearly relatedand, therefore, one hardness value cannot easily be correlated to theother.

Compositions described herein have a Shore D hardness of at least about30, and preferably about 40 to 60, as measured on a formed sphere. Thecompositions preferably have a Shore D hardness of about 50 to 65, asmeasured on a standard test plaque.

Flexural Modulus

The flexural and/or tensile modulus of an intermediate layer of a golfball is believed to have an effect on the “feel” of the ball. Thecompositions described herein have a flexural modulus of about 15,000psi to about 30,000 psi.

The selection of compositions with specific resilience, compression,hardness and/or flexural modulus will largely depend upon the type ofgolf ball desired (i.e., two-piece, wound, or multilayered), and in thetype of performance desired for the resulting golf ball as detailedabove.

The thermoplastic compositions described herein may be useful in a widerange of objects other than, mantles, intermediate layers, cores, andcenters of golf balls. As previously discussed, the compositions, andoptionally foamed compositions, may be used as cores for balls otherthan golf balls. The compositions also may be useful in other sportingequipment applications, particularly in golf shoe cleats, components ofgolf clubs such as golf club face plates or inserts, molded golf clubheads, club head coatings or casings, and fillers for inner cavity of agolf club head, and the like. The compositions may also be used in placeof materials taught in the art for use in club faces, such aspoly-imides reinforced with fillers or fibers, methyl (meth)acrylatecopolymers, carbon-fiber reinforced polycarbonate, materials based onPMMA and crosslinkable monomers, and cross-linked synthetic rubber. Thecomposition may also be substituted for the cured acrylic monomer,oligomer, polymer used to impregnate wood club heads, for rubber-likeelastic cores in club heads, and for molded polyurethane club heads. Assuch, golf club heads may be prepared having a front striking faceadapted to strike a ball and an insert mounted on the striking face,said insert comprising a molded article comprising the compositionabove. In addition, golf club heads comprising a metal body and aninsert plate secured to the forward striking surface of the metal bodyand made of the composition above laminated with an outer metal layerformed with grooves. In addition, this invention also includes a golfclub having a shaft with a club head affixed to the shaft, wherein theclub head is described above, having a component comprising thecomposition above.

The composition may also be useful for preparing molded articles thatare footwear structural components, provide shape support for footwearconstruction, such as heel counters, toe puffs, soles and cleats. “Heelcounter” as used herein refers to a stiff, curved piece that providesshape and structure to the heel area of a shoe. “Toe puff” or “toe box”as used herein refers to a stiff, arched piece that provides shape andstructure to the toe area of a shoe. “Sole” as used herein refers to astiff, generally flat piece that provides shape and structure to thebottom of a shoe. These structural components may be incorporated intothe internal structure of the shoe and covered with additionalcomponents for wear and/or appearance.

The composition described herein may also be useful in non-sporting goodapplications such as caulking materials, sealants, modifiers for cementand asphalt, and coatings. The compositions may also be useful in toys,decorative objects, and containers for inert materials.

The following examples are provided to describe the invention in furtherdetail. These examples, which set forth a preferred mode presentlycontemplated for carrying out the invention, are intended to illustrateand not to limit the invention.

EXAMPLES Testing Criteria for Examples

Coefficient of Restitution (COR) was measured by firing aninjection-molded neat sphere of the resin having the size of a golf ballfrom an air cannon at several velocities over a range of roughly 60 to180 fps. The spheres struck a steel plate positioned three feet awayfrom the point where initial velocity is determined, and reboundedthrough a speed-monitoring device located at the same point as theinitial velocity measurement. The COR of each measurement was determinedas the ratio of rebound velocity to initial velocity. The individuallydetermined COR measurements were plotted as a function of initialvelocity, and COR at 125 fps (i.e. COR₁₂₅) was determined by linearregression.

As used in the Examples below, melt index (MI) refers to melt index asdetermined according to ASTM D1238 at 190° C. using a 2160 g weight,with values of MI reported in g/10 minutes.

As used herein, “Shore D hardness” of a material is measured generallyin accordance with ASTM D-2240 either on a plaque or on the curvedsurface of a molded sphere. Shore D hardness of multilayer spheres ismeasured with all layers present. When a hardness measurement is made ona dimpled sphere, Shore D hardness is measured at a land area of thedimpled sphere.

Flex Modulus was measured according to ASTM D790, Method 1, Procedure A,employing a 3-point test fixture with a 2-inch span length and acrosshead speed of 0.50 inches/minute. The method provides a measurementof the Tangent Modulus of Elasticity (3-Point Flex Modulus).

PGA Compression was measured using an “Atti” testing device according tostandard procedures for that instrument. For accurate comparison ofcompression data, the diameter of the balls was corrected to 1.68 inchdiameter using accepted methods, such as shimming.

Materials Used:

-   EAC-1: An ethylene methacrylic acid (MAA) dipolymer with 20 weight %    of MAA, with MI of 500.-   EAC-2: An ethylene methacrylic acid (MAA) dipolymer with 19 weight %    of MAA, with MI of 305.-   EAC-3: An ethylene methacrylic acid (MAA) dipolymer with 19 weight %    of MAA, with MI of 250.-   EAC-4: An ethylene acrylic acid (AA) dipolymer with 21 weight % of    AA, with an MI of 300.-   EAC-5: An ethylene acrylic acid (AA) dipolymer with 18 weight % of    AA, with an MI of 60.-   EAC-6: An ethylene acrylic acid (AA) dipolymer with 15.4 weight % of    AA, with an MI of 80.-   MB-1: A Mg(OH)₂ concentrate with 49 weight % Mg(OH)₂ in an ethylene    acrylic acid (AA) n-butyl acrylate (nBA) terpolymer having 6.2    weight % AA and 28.0 weight % nBA, with MI of 300.-   MB-2: A Mg(OH)₂ concentrate with 50 weight % Mg(OH)₂ in an ethylene    methacrylic acid (MAA) dipolymer having 5 weight % MAA, with MI of    500.-   Filler: crystalline tungsten powder, with specific gravity of 19.3    g/cc, available from ATI Alldyne Powder Technologies of Huntsville,    Ala., or Kulite Tungsten Corporation of East Rutherford, N.J.-   Oleic acid, commercial grade from PMC Biogenix under the tradename    INDUSTRENE 106.-   “PBR” refers to a conventional filled thermoset polybutadiene rubber    core. In the Tables below, “NA” means “not available”.

Blends were prepared according to the following general procedure.

Employing a Werner & Pfleiderer twin screw extruder, oleic acid, anethylene acid dipolymer, and neutralizing agent (MB-1, MB-2 and/or Mg(OH)₂) were melt blended. The amounts of the acid and copolymer wereadded so that the resulting blend contained 35 to 45 weight % of theoleic acid. The blend was treated with sufficient MB-1, MB-2 and/or Mg(OH)₂ so that the acid moieties of the organic acid and the acidcopolymer were nominally neutralized to the level indicated.

Extrusion conditions for making the blends identified in Table 2 areshown in Table 1.

TABLE 1 Zone 1 Zone 2-4 Zone 5 Die Melt Temperature ° C. 140-180 265-275255-265 200-220 255-275 Vacuum inches 28 Screw Speed rpm 175-250 Totalrate (lb/h) 15-25

The components of the blends are summarized in Table 2. ComparativeExamples C14-16 are blends comprising a high acid ethylene copolymerwith lower MI, neutralized with Mg(OH)₂ to less than 100% nominalneutralization, prepared using procedures similar to those used for theExamples. Except for Example 3 and Comparative Example C14 where theMg(OH)₂ was added directly as a powder, the Mg(OH)₂ was added using amasterbatch. The amount of Mg(OH)₂ added is related to its concentrationin the masterbatch. The column labeled “Mg(OH)₂” shows the amount ofMg(OH)₂ calculated to be present in the composition based on the amountof MB-1 or MB-2 added. “% Nominal Neutralization” is calculated from theamount of acid groups present in the dipolymer, the amount of organicacid, and the amount of Mg(OH)₂.

TABLE 2 Weight % Dipolymer Oleic % Nominal Measured Example usedDipolymer Acid MB-1 Mg(OH)₂ Neutralization MI 1 EAC-1 35.40 39.90 24.7012.10 178 0.72 2 EAC-1 38.15 38.30 23.55 11.55 170 0.59 3 EAC-1 54.0135.86 0.00 10.13 139 0.63 4 EAC-1 40.90 36.70 22.40 11.00 162 0.45 5EAC-2 39.70 41.10 19.20 9.41 134 1.20 6 EAC-2 34.50 41.40 24.10 11.80174 0.75 7 EAC-2 39.70 41.10 19.20 9.41 134 0.26 8 EAC-2 38.80 39.0022.20 10.85 160 0.61 9 EAC-2 42.80 36.90 20.30 9.90 146 0.50 10  EAC-231.14 46.00 22.86 11.20 160 0.62 11  EAC-3 36.22 39.90 23.88 11.70 1740.96 12  EAC-3 47.37 35.00 17.63 8.64 126 1.20 13  EAC-4 44.33 36.8419.84 9.72 125 0.03 C14 EAC-5 57.5  36.00 0   6.50 81 0.8 20  EAC-549.60 34.82 15.58 7.94 150 0.22 40.42 21  EAC-5 44.93 Erucic 14.65 7.56153 0.46 acid MB-2 C15 EAC-5 45.00 40.00 15.00 7.50 97 0.75 C16 EAC-645.72 40.00 14.28 7.14 98 0.38

In addition, the compositions prepared in Examples 2 and 8 were filledwith tungsten filler (Table 3). Fillers were added on a twin screwextruder at conditions to melt the polymer composition and incorporatethe filler. Filler was either added to the back end of the extruder withthe pellet feed or at a downstream feed port along the extruder barrel.“Resin Volume %” is the percentage of the total volume of thecomposition occupied by the non-filler components.

TABLE 3 Example Non-filled Composition Resin Volume % 17 Example 2 98.518 Example 2 97.4 19 Example 8 98.5

Thermoplastic Spheres

The compositions were molded into spheres 1.53 to 1.55 inches indiameter using the molding conditions shown in Table 4. General moldingconditions are reported as ranges, with specific conditions for selectedexamples indicated. The example spheres are summarized in Table 5.

TABLE 4 Molding Conditions for Spheres Melt Zone Mold Inject Fill PackPack Cool Example (° C.) (° C.) (s) (s) (s) (mPa) (s) General 190-23020-50 80-90 10-30 55-75 50-160 75-80 3 227 24 85.0 20.9 64.1 86.2 80.0 4213 27 80.0 21.9 58.1 93.6 75.0 6 213 27 80.0 22.0 58.1 83.1 75.0 7 19621 85.0 20.3 64.7 149.2 80.0 9 213 27 80.0 21.7 58.3 100.1 75.0 17  22424 85.0 13.2 71.8 121.4 80.0 18  224 24 85.0 13.1 71.9 129.7 80.0

TABLE 5 Specific Example Diameter (in) Mass (g) Gravity (g/cc)  1 1.542832.015 1.012  2 1.5507 32.007 0.999  3 1.5360 30.910 0.994  4 1.542931.680 1.004  5 1.5382 31.279 1.002  6 1.5407 31.669 1.012  7 1.524230.415 1.003  8 1.5068 29.488 0.992  9 1.5404 31.183 0.995 10 1.537730.772 0.986 11 1.5364 31.215 1.003 12 1.5427 30.121 0.955 13 1.546731.450 0.989 C14 NA NA NA C15 NA NA NA C16 NA NA NA 17 1.5340 37.3011.204 18 1.5270 41.868 1.366 19 1.5331 37.316 1.205 20 1.561  30.7050.940 21 1.563  30.459 0.930 PBR 1.552  37.158 1.158

The spheres were tested for Coefficient of Restitution, PGA Compressionand Shore D Hardness. Compositions were also compression molded intostandard test plaques 0.125 inches thick and cut into specimens 0.5inches wide and 3 to 5 inches in length to measure flex modulus andShore D hardness. The samples were conditioned for two weeks at ASTM labconditions (73° F. and 50% RH). The results are reported in Tables 6 and7. In Table 7, “COR loss” is the difference in COR between the unfilledand filled compositions (Examples 15 and 16 compared to Example 2 andExample 17 compared to Example 8).

TABLE 6 Plaque Sphere Flexural PGA Shore D Modulus Shore D ExampleCOR₁₂₅ Compression Hardness (psi) Hardness 1 0.867 119.3 48.5 20,468 552 0.866 120.4 52.0 21,543 57 3 0.864 130.1 56.0 24,522 60 4 0.862 128.250.6 20,957 57 5 0.868 114.5 48.1 16,839 54 6 0.867 115.6 47.1 20,142 567 0.866 116.1 51.3 20,042 57 8 0.865 127.6 51.0 20,877 57 9 0.863 119.349.6 21,498 57 10  0.862 115.4 49.2 18,383 54 11  0.862 108.6 47.417,226 56 12  0.860 95.9 53.0 20,824 57 13  0.884 129.1 58.7 NA NA C140.819 122 NA 20,600 57 C15 0.818 124.6 NA NA NA C16 0.821 115.1 NA NA NA20  0.867 107.7 55.9 NA NA 21  0.872 96.9 50.1 NA NA

TABLE 7 Plaque Sphere Flexural Shore D Ex- COR PGA Shore D Modulus Hard- ample COR₁₂₅ Loss Compression Hardness (psi) ness 17 0.853 0.013124.9 53.4 21,665 57 18 0.839 0.027 123.9 52.9 21,343 57 19 0.856 0.009123.1 53.8 21,596 57 PBR 0.692 NA 65.0 40.2 NA NA

While certain of the preferred embodiments of the present invention havebeen described and specifically exemplified above, it is not intendedthat the invention be limited to such embodiments. Various modificationsmay be made without departing from the scope and spirit of the presentinvention, as set forth in the following claims.

1. A golf ball comprising a core and a cover and optionally at least oneintermediate layer positioned between the core and the cover, whereinthe core or the intermediate layer when present comprises or is preparedfrom a thermoplastic composition, said thermoplastic compositionoptionally comprising a filler; wherein the thermoplastic compositionhas a PGA compression greater than 100; and further wherein thethermoplastic composition when formed into a sphere of 1.50 to 1.68inches in diameter has a coefficient of restitution, said coefficient ofrestitution being measured by firing the sphere at an initial velocityof 125 feet/second against a steel plate positioned 3 feet from thepoint where initial velocity is determined and dividing the velocity ofrebound from the plate by the initial velocity; wherein the coefficientof restitution is equal to or greater than 0.860 when the thermoplasticcomposition does not comprise filler; and wherein the coefficient ofrestitution is equal to or greater than 0.830 when the thermoplasticcomposition comprises filler.
 2. The golf ball of claim 1 wherein thecoefficient of restitution is equal to or greater than 0.870 or 0.875.3. The golf ball of claim 1 wherein the thermoplastic compositioncomprises or is prepared from: (a) at least one aliphatic,monofunctional organic acid having 4 to 36 carbon atoms, wherein thelongest carbon chain of the acid is optionally substituted with from oneto three substituents independently selected from C₁ to C₈ alkyl groups;(b) an ethylene acid copolymer consisting essentially of copolymerizedcomonomers of ethylene and from 18 to 24 weight % of copolymerizedcomonomers of at least one C₃ to C₈ α,β ethylenically unsaturatedcarboxylic acid, based on the total weight of the ethylene acidcopolymer, said ethylene acid copolymer having a melt index from about200 to about 600 g/10 minutes measured before neutralization accordingto ASTM D1238 at 190° C. using a 2160 g weight; and wherein the combinedacid moieties of (a) and (b) are nominally neutralized to a level fromabout 120% to about 200%.
 4. The golf ball of claim 3 wherein theorganic acid is present in from about 35 to about 46 weight % of thetotal composition.
 5. The golf ball of claim 3 wherein the organic acidcomprises a linear, unsaturated organic acid having from 16 to 24 carbonatoms.
 6. The golf ball of claim 5 wherein the organic acid comprisesoleic acid.
 7. The golf ball of claim 3 wherein the C₃ to C₈ α,βethylenically unsaturated carboxylic acid is acrylic acid or methacrylicacid or a combination of acrylic acid and methacrylic acid.
 8. The golfball of claim 3 wherein the thermoplastic composition comprises filler;or wherein the golf ball has a cover prepared from a polyurethanecomposition or an ionomer composition.
 9. The golf ball of claim 8wherein the filler comprises tungsten, barium sulfate, titanium or zincoxide.
 10. The golf ball of claim 8 wherein the core comprises thethermoplastic composition.
 11. The golf ball of claim 8 comprising theoptional intermediate layer, said optional intermediate layer comprisingthe thermoplastic composition.
 12. The golf ball of claim 1 wherein thecore comprises the thermoplastic composition.
 13. The golf ball of claim1 comprising the optional intermediate layer, said optional intermediatelayer comprising the thermoplastic composition.
 14. A thermoplasticcomposition comprising or prepared from: (a) at least one aliphatic,monofunctional organic acid having 4 to 36 carbon atoms, optionallysubstituted with from one to three substituents independently selectedfrom C₁ to C₈ alkyl groups; (b) an ethylene acid copolymer consistingessentially of copolymerized comonomers of ethylene and from 18 to 24weight % of copolymerized comonomers of at least one C₃ to C₈ α,βethylenically unsaturated carboxylic acid, based on the total weight ofthe ethylene acid copolymer, having a melt index from about 200 to about600 g/10 minutes measured according to ASTM D1238 at 190° C. using a2160 g weight; wherein the combined acid moieties of (a) and (b) arenominally neutralized to a level from about 120% to about 200%; andoptionally (c) filler.
 15. The composition of claim 14 wherein theneutralized organic acid is present in from about 35 to about 45 weight% of the total composition.
 16. The composition of claim 14 wherein theorganic acid comprises a linear, unsaturated organic acid having from 16to 24 carbon atoms.
 17. The composition of claim 14 wherein the organicacid comprises oleic acid.
 18. The composition of claim 14 wherein theC₃ to C₈ α,β ethylenically unsaturated carboxylic acid is acrylic acidor methacrylic acid or a combination thereof.
 19. The composition ofclaim 14 having a PGA compression greater than 100 and a coefficient ofrestitution that is measured by forming a sphere of 1.50 to 1.68 inchesin diameter and firing the sphere at an initial velocity of 125feet/second against a steel plate positioned 3 feet from the point whereinitial velocity is determined and dividing the velocity of rebound fromthe plate by the initial velocity; wherein the coefficient ofrestitution is equal to or greater than 0.860 when the composition doesnot comprise filler; and wherein the coefficient of restitution is equalto or greater than 0.830 when the composition comprises filler.
 20. Thecomposition of claim 19 wherein the composition does not comprise fillerand the coefficient of restitution is equal to or greater than 0.870 or0.875.
 21. The composition of claim 14 wherein the filler comprisestungsten, barium sulfate, titanium or zinc oxide.
 22. An articlecomprising the composition of claim 14, wherein the composition isfoamed by the addition of at least one physical or chemical blowing orfoaming agent or by blending with polymeric, ceramic, metal, and glassmicrospheres.
 23. The article of claim 22 that is a golf ball or otherball comprising a core or center prepared from the composition.